How can identifying the author and or sponsor of a site help you determine whether or not information on that site is biased?

By looking up previous things they have said in other different pieces of text.

Comparing them, decide if you think they are biased, give your reasons in a list of Why it is biased and Why it is not Biased, if you Why it is outrules your It Is then you will know, if this is for school I have no ing clue.